8
Pump Repair Instructions - GP8155/GP8160/GP8165
6) Remove tension screw (36C) and take
seal sleeve (39) together with all mounted
parts out of the drive. Pull plunger pipe (36B)
out of the seal assembly and check for any
damage. Carefully, remove seal rings (40) and
sleeves (42) with a screwdriver.
4) Remove valve assembly (52) from discharge valve adapter (56) by gently twisting apart. The spring
tension cap (51A, 52A) is screwed together with the valve seat (51B or 52B). Remove spring tension cap.
Takeout springs (51E, 52E) and valve plate (51C, 52C). Check sealing surfaces of valve plates (51C &
52C) and valve seats (51B & 52B) and O-rings (51D, 52D). Replace worn parts. Coat threads of valve seat
with silicon grease or molycote anti-seize Cu-7439 when reassembling. Before refitting the valves, clean
the sealing surfaces in the casing and check for any damage. Coat o-rings (51D, 52D & 56A) with silicone
grease to help with re-assembly. Replace valve assembly (51) and pressure spring (57). Assemble valve
assembly (52) to discharge valve adapter (56) by tapping together lightly with rubber mallet. While replacing
the valve assemblies use a rubber mallet to tap the top of the valve puller lightly. This insures proper seat
-
ing. Replace pressure spring (57A) and the discharge casing (50B). Tighten caps (58) at 132 Ft-lbs. (180
Nm); check torque tension after 8-10 operating hours.
5)
Remove hexagon nuts (49A) and valve
casing together with seal case (38) from
crankcase (1). If necessary, carefully tap the
valve casing (50) past the centering stud
(50A) using a rubber hammer.
IMPORTANT!
If necessary, support the valve
casing by resting it on wooden blocks or by
using a pulley.
Valve Inspection and Repair
1) Remove socket head cap
screws (58)
2) Lift discharge casing
(50B) up and away.
3) Take out pressure springs
(57A). Pull out assembled
valves (51 & 52) with valve puller.
To Check Seals and Plunger Pipe
